### Please describe the problem.

As I understand the manual:

- Options `--json --json-error-messages` are provided so that another program can parse the `git annex fsck` results. 

- Option `--quiet` is provided to list only problems (not print anything for OK files). 

However, when options are combined, only plain text error messages are provided, no json output is provided.

I understand this may be "as designed", quiet is quiet... But then how to log only errors in json? I have +300k files in the annex, and no need to log when everything is fine.

### What steps will reproduce the problem?

Create a repo with files b and c 

Corrupt file b
 
`git annex fsck  --json --json-error-messages --quiet`

I expected to have a json output with only files that fail the fsck, instead I get only normal stderr, just like with 
`git annex fsck  --quiet`

### What version of git-annex are you using? On what operating system?
10.20230926-12 on arch

### Please provide any additional information below.

[[!format sh """

# Expected plain result 
> git annex fsck

fsck b 
  ** No known copies exist of b
failed
fsck c (checksum...) ok
(recording state in git...)
fsck: 1 failed

# Expected json result (error message to stderr, both logs)
> git annex fsck --json

  ** No known copies exist of b
{"command":"fsck","dead":[],"error-messages":[],"file":"b","input":["b"],"key":"SHA256E-s5--f2ca1bb6c7e907d06dafe4687e579fce76b37e4e93b7605022da52e6ccc26fd2","success":false,"untrusted":[]}
{"command":"fsck","error-messages":[],"file":"c","input":["c"],"key":"SHA256E-s4--530a0b93b8c1ea618546d3aaa6ec71f888d2a6095322bfdb1b04c9225e26481e","note":"checksum...","success":true}
fsck: 1 failed

# Expected json output with error message embedded 
> git annex fsck  --json --json-error-messages

{"command":"fsck","dead":[],"error-messages":["** No known copies exist of b"],"file":"b","input":["b"],"key":"SHA256E-s5--f2ca1bb6c7e907d06dafe4687e579fce76b37e4e93b7605022da52e6ccc26fd2","success":false,"untrusted":[]}
{"command":"fsck","error-messages":[],"file":"c","input":["c"],"key":"SHA256E-s4--530a0b93b8c1ea618546d3aaa6ec71f888d2a6095322bfdb1b04c9225e26481e","note":"checksum...","success":true}
fsck: 1 failed

# Expected only error message
> git annex fsck --quiet

  ** No known copies exist of b
fsck: 1 failed

# UnExpected result: I expected a json output with the error message embedded "--json --json-error-messages" seem ignored here
> git annex fsck  --json --json-error-messages --quiet

  ** No known copies exist of b
fsck: 1 failed

# End of transcript or log.
"""]]

### Have you had any luck using git-annex before? (Sometimes we get tired of reading bug reports all day and a lil' positive end note does wonders)

Yes, great tool ! Thanks !


> [[wontfix|done]] per my comment --[[Joey]]
